Proper soil management periodically requires the injection of additives into the soil at predetermined depths. One such additive is anydrous ammonia used to supply available nitrogen for crops. Anhydrous ammonia is stored in tanks under pressure to maintain it in liquid form. When discharged from storage tanks, a substantial portion of the anhydrous ammonia vaporizes and is lost to the atmosphere unless it is entrapped in the soil.
Anhydrous ammonia is generally applied to the soil at a depth of about 3-5 inches by anhydrous ammonia knives. A number of knives are mounted on an implement tool bar and spaced on the bar at intervals perpendicular to the direction of travel over the field. A delivery tube, typically mounted on the rear edge of each knife, carries anhydrous ammonia from an implement storage tank and discharges it at an outlet below the surface of the soil. As the implement travels forward over the field, each knife cuts a furrow in front of the delivery tube discharge and a regulated amount of ammonia is deposited in the furrow. As the ammonia discharges from the tube it is typically 75-85% liquid and 15-25% gas. To avoid loss of the ammonia gas, it must be promptly and effectively entrapped in the soil.
Those concerned with these and other problems recognize the need for an improved anhydrous ammonia knife.